1. Technical Field
The present invention relates generally to a drive line apparatus for automotive vehicles, and more particularly to a drive line apparatus including, for example, an automatic transmission device composed of a clutch and a parallel-shaft type gear transmission.
2. Background Art
A manual transmission device using a clutch and a parallel-shaft type gear transmission is well known in the art. This transmission device is inferior to an automatic transmission using a torque converter in ease of operation, but is superior in transmission efficiency of power and response rate.
Japanese Patent First Publication No. 60-215429 teaches an automatic transmission device having the advantages of the manual transmission device, as described above, which disconnects a power transmission line extending from an engine to an output shaft of a transmission when an upshift is made, returns a throttle valve to a fully-closed position with the aide of spring activity, and activates a starter motor as a generator to apply a load on the engine for establishing synchronization of the engine and the output shaft of the transmission, thereby shortening a shifting time.
The above conventional automatic transmission device, however, encounters the following drawback.
Since the power transmission line from the engine to the output shaft of the transmission is disconnected when the upshift is achieved, a load acting on the engine is decreased. Thus, even if an additional load is applied on the engine by controlling the throttle valve and the generator, the synchronization of the engine and the output shaft of the transmission is delayed, requiring an extended period of time for the shifting. Additionally, if the power transmission line from the engine to the output shaft of the transmission is engaged even though the engine is out of synchronization with the output shaft of the transmission for shortening the shifting time, it will cause large scale mechanical shock to be generated during the engagement of the power transmission line.